Microgel-containing composition

ABSTRACT

The present invention relates to a composition containing thermoplastic materials and crosslinked microgels that have not been crosslinked by high-energy radiation, to a process for its preparation, to its use in the production of thermoplastically processable molded articles, and to molded articles produced from the composition.

The present invention relates to a composition containing thermoplasticmaterials and crosslinked microgels that have not been crosslinked byhigh-energy radiation, to a process for its preparation, to its use inthe production of thermoplastically processable molded articles, and tomolded articles produced from the composition.

BACKGROUND OF THE INVENTION

The use of microgels for controlling the properties of elastomers isknown (e.g. EP-A-405216, DE-A 4220563, GB-PS 1078400, DE 19701487, DE19701489, DE 19701488, DE 19834804, DE 19834803, DE 19834802, DE19929347, DE 19939865, DE 19942620, DE 19942614, DE 10021070, DE10038488, DE 10039749, DE 10052287, DE 10056311 and DE 10061174).EP-A-405216, DE-A-4220563 and GB-PS-1078400 disclose the use of CR, BRand NBR microgels in mixtures with double-bond-containing rubbers. DE19701489 describes the use of subsequently modified microgels inmixtures with double-bond-containing rubbers such as NR, SBR and BR.

None of these specifications teaches the use of microgels in theproduction of thermoplastic elastomers.

Chinese Journal of Polymer Science, Volume 20, No. 2, (2002), 93-98describes microgels that have been completely crosslinked by high-energyradiation and their use to increase the impact strength of plastics.Similarly, US 20030088036 A1 discloses reinforced heat-curing resincompositions in whose preparation radiation-crosslinked microgelparticles are likewise mixed with heat-curing pre-polymers (see also EP1262510 A1). In these publications, a radioactive cobalt source ismentioned as the preferred radiation source or the preparation of themicrogel particles. The use of radiation crosslinking yields veryhomogeneously crosslinked microgel particles. However, this type ofcrosslinking has the particular disadvantage that it is not realistic totransfer this process from a laboratory scale to a large-scaleinstallation both from an economic viewpoint and from the point of viewof working safety. Microgels that have not been crosslinked byhigh-energy radiation are not used in the mentioned publications.Furthermore, when completely radiation-crosslinked microgels are used,the change in modulus from the matrix phase to the dispersed phase isimmediate. In the case of sudden stress, this can lead to tearingeffects between the matrix and the dispersed phase, with the result thatthe mechanical properties, the swelling behavior and the stresscorrosion cracking, etc. are impaired.

DE 3920332 discloses rubber-reinforced resin compositions which comprise(i) a matrix resin having a glass transition temperature of at least 0°C. and (ii) from 1 to 60 wt. % of rubber particles dispersed in thematrix resin. The dispersed particles are characterized in that theyconsist of hydrogenated block copolymers of a conjugated diene and avinyl aromatic compound. The particles inevitably have two glasstransition microphase structure of separate microphase with segments andtemperatures, one being at −30° C. or less. The particles exhibit a softsegments, in which the hard segments and the soft segments arealternately laminated with one another in the form of concentricmultiple layers. The preparation of these specific particles is veryexpensive because it is first necessary to prepare a solution of thestarting materials for the particles (block copolymers) in organicsolvents. In the second step, water and optionally emulsifiers areadded, the organic phase is dispersed in suitable apparatuses, thesolvent is then removed and the particles dispersed in water are thenfixed by crosslinking with a peroxide. In addition, it is very difficultto produce particle sizes less than 0.25 μm by this process, which isdisadvantageous for the flow behavior.

Polymeric materials can be divided into several groups according totheir structure, their deformation-mechanical behavior and henceaccording to their properties and fields of use. Traditionally there areon the one hand the amorphous or semi-crystalline thermoplastics, whichconsist of long, uncrosslinked polymer chains. Thermoplastics arebrittle to viscoelastic at room temperature. These materials areplasticized by pressure and temperature and can then be molded. On theother hand there are the elastomers or rubber materials. Elastomers area crosslinked rubber product. It may be natural or synthetic rubber.Rubbers can only be processed in the uncrosslinked state. They thenexhibit viscoplastic behavior. Only with the addition of crosslinkingchemicals such as, for example, sulfur or peroxide is there obtainedupon subsequent heating a vulcanization product or the elastic rubber.In this “vulcanization procedure”, the loosely fixed individual rubbermolecules are linked together chemically by the formation of chemicalbonds. The amorphous preliminary product rubber changes hereby into theelastomer with typical rubber elasticity. The vulcanization procedure isnot reversible, except by thermal or mechanical decomposition.

The thermoplastic elastomers (abbreviated to TPE herein below) exhibitcompletely different behavior. These materials become plastic whenheated and elastic again when cooled. In contrast to chemicalcrosslinkinq, crosslinking in the case of elastomers is physicalAccordingly, the TPEs stand between the thermoplastics and theelastomers in terms of their structure and their behavior, and theycombine the ready processability of the thermoplastics with thefundamental properties of rubber. Above Tg to the melting point or tothe softening temperature, the TPEs behave like elastomers, but they arethermoplastically processable at higher temperatures. As a result ofphysical crosslinking, for example via (semi-)crystalline regions, athermoreversible structure with elastic properties is formed on cooling.

In contrast to the processing of rubber, the processing of TPE materialsis based not on a cold/warm process but on a warm/cold process. If inthe case of soft, highly elastic TPE materials in particular thepronounced intrinsically viscous melting or softening behavior is takeninto account, then it is possible when processing TPEs to use thetypical thermoplastic processes such as injection molding, extrusion,blow molding and deep drawing. The product properties depend primarilyon the structure and phase morphology; in elastomer alloys a large partis played, for example, by the particle size, the particle sizedistribution or the particle stretching of the disperse phase. Thesestructural features can be influenced to a certain extent duringprocessing. A further fundamental advantage of TPE materials over theconventional, chemically crosslinked elastomers can be seen in theirfundamental suitability for recycling. As with all plastics, a fall inviscosity that increases with the number of processing steps is to beobserved in the case of the TPE materials, but this does not lead to asignificant impairment of the product properties.

Since the discovery of the TPEs, this class of materials has beendistinguished by the fact that it is formed by a combination of a hardphase and a soft phase. The TPEs known hitherto are divided into twomain groups:

-   -   block copolymerization products and    -   alloys of thermoplastics with elastomers.        Block Copolymerization Products:

The composition of the comonomers determines the ratio of hard phase tosoft phase, determines which phase constitutes the matrix and determinesthe final properties. A true morphology is recognizable at molecularlevel when, for example, the deficient component aggregates orcrystallizes. The temperature dependence of this physical morphologyfixing is a problem with these materials, that is to say there is alimit temperature at which the morphology fixing is undone. This cancause problems during processing owing to changes in the propertiesassociated therewith.

The block polymers include, for example, styrene block copolymers(TPE-S), such as butadiene (SBS), isoprene (SIS) and ethylene/butylene(SEBS) types, polyether-polyamide block copolymers (TPE-A),thermoplastic copolyesters, polyether esters (TPE-E) and thermoplasticpolyurethanes (TPE-U), which are described in greater detail hereinbelow in connection with the starting materials that can be usedaccording to the present invention.

The second main group of the material TPE are the elastomer alloys.Elastomer alloys are polymer blends which contain both thermoplastic andelastomeric constituents. They are prepared by “blending” the rawmaterials, that is to say mixing them intensively in a mixing device(internal mixer, extruder or the like). Very different mixing ratiosbetween the hard phase and the soft phase can occur. The soft phase canbe either uncrosslinked (TPE-0) or crosslinked (TPE-V). In the ideal TPEblend there are small elastomer particles which are uniformlydistributed in finely dispersed form in the thermoplastic matrix. Thefiner the distribution and the higher the degree of crosslinking of theelastomer particles, the more pronounced the elastic properties of theresulting TPE. These TPE blends are prepared, for example, by so-called“dynamic vulcanization” or reactive extrusion, in which the rubberparticles are crosslinked in situ during the mixing and dispersingprocess. The property profile of these blends is accordinglysubstantially dependent on the proportion, degree of crosslinking anddispersion of the rubber particles. Very different combinations can beproduced by this blend technology. The physico-mechanical properties andthe chemical resistance and compatibility with contact media aresubstantially determined by the individual properties of the blendcomponents. By optimizing the “blend quality” and the degree ofcrosslinking it is possible to improve specific physical properties.Nevertheless, it is a characteristic of this class that the dispersedphase is present in irregular and coarsely dispersed form. The lesscompatible the polymers, the more coarse the resulting structure. Thenon-compatible combinations, such as, for example, a dispersed phase ofNBR rubber in a PP matrix, are of particular technical interest. Inorder to improve the compatibility in such cases and accordinglyinfluence the final properties of the resulting material in the desiredmanner, a homogenizing agent can be added prior to the dynamicvulcanization. About 1% of the homogenizing agent is sufficient for manyapplications. The homogenizing agents are generally based on blockcopolymers whose blocks are compatible with in each case one of theblend phases. Depending on the relative proportions, the two phases mayconstitute both the continuous and the discontinuous phase. Hitherto ithas not been possible to adjust the morphology of this material in areliable manner. In order to produce particularly finely divideddispersed phases, large amounts of the homogenizing agent may benecessary, which in turn adversely affects the boundary properties ofthe final material. Industrially produced and commercially availablethermoplastic vulcanization products exhibit a maximum distribution ofthe diameter of the dispersed phase of from 2 μm to 4 μm with individualvolume elements up to 30 μm.

Among the elastomer alloys, the most commonly used combinations arebased on EPDM with PP. Other elastomer alloys are based on NR/PP blends(thermoplastic natural rubber), NBR/PP blends(NBR=acrylonitrile-butadiene rubber), IIR (XIIR)/PP blends (butyl orhalobutyl rubbers as elastomeric phase constituents), EVA/PVDC blends(“Alcryn” blend of ethylene-vinyl acetate rubber (EVA) andpolyvinylidene chloride (PVDC) as the thermoplastic phase) and NBR/PVCblends. A targeted adjustment of the morphology of the dispersed phaseand hence a targeted adjustment of the desired properties of the TPEs inthese polymer blend TPEs is virtually impossible, however, owing to thein situ formation of the dispersed phase and the many parametersinvolved therein.

The present inventors relates to novel compositions having thermoplasticelastomer properties which can easily be prepared from startingmaterials known per se and whose properties can be adjusted in a simpleand foreseeable manner. The novel compositions can be prepared on anindustrial scale, and they should not give rise to problems relating toworking safety. Furthermore, there should be no tearing effects in thecompositions between the matrix and the dispersed phase on sudden stressso that the mechanical properties, the swelling behavior and the stresscorrosion cracking, etc. are impaired. The preparation of the microgelsfor the composition should be simple and allow the particle sizedistributions of the microgel particles to be adjusted in a targetedmanner to very small average particle sizes.

SUMMARY OF THE INVENTION

Surprisingly it has been found in the present invention that, byincorporating crosslinked microgels, which have not been crosslinked byhigh-energy radiation, based on homopolymers or random copolymers intothermoplastic materials, it is possible to provide compositions having anovel combination of properties. By the provision of the novelcomposition it is surprisingly possible to overcome the above-mentioneddisadvantages of the known conventional thermoplastics and TPEs and atthe same time provide thermoplastic elastomer compositions havingoutstanding use properties. Because thermoplastic elastomer compositionsare obtained by the incorporation of microgels into the thermoplasticmaterials, it is possible to separate the adjustment of the morphologyof the dispersed phase from the production of the TPE material in termsof both space and time. The morphology production can be reliablyreproduced because the dispersed phase is a microgel whose morphologycan be controlled in a manner known per se during preparation and whichsubstantially does not change further on incorporation into thethermoplastic material. In the compositions prepared according to theinvention, the polymer microstructure of both the dispersed phase andthe continuous phase can be varied within wide limits, so thatcustomized TPEs can be produced from any desired thermoplasticmaterials, which was not possible according to the known processes forthe production of conventional TPEs. By controlling the degree ofcrosslinking and the degree of fictionalization in the surface and inthe core of the dispersed microgels, the desired properties of theresulting TPEs can be controlled further. The glass transitiontemperature of the dispersed microgel phase can also be adjusted in atargeted manner within the range of from −100° C. to less than 50° C.,as a result of which the properties of the resulting TPEs can in turn beadjusted in a targeted manner. As a result, the difference in glasstransition temperature between the dispersed phase and the continuousphase can also be adjusted in a targeted manner and can be, for example,from 0° C. to 250° C. With the novel class of TPEs provided by thepresent invention it is additionally possible to combinethermodynamically compatible and thermodynamically incompatible polymersto form new TPEs which were not obtainable by conventional processes. Inthe novel TPEs provided by the present invention, the dispersed phaseand the continuous phase may each constitute the hard phase and the softphase. By controlling the properties of the microgels and the relativeproportions, the dispersed phase can be present in the matrix in theform of aggregated clusters or in uniformly distributed form and in allintermediate forms.

This is not possible in the TPEs prepared by conventional processes, inwhich the dispersed phase is formed in situ during the production of theTPEs.

Furthermore, it has been surprisingly found not only that theincorporation of microgels into thermoplastic plastics permits theproduction of thermopastic elastomers, but also that the incorporationof microgels into, for example, thermoplastic elastomers produced byconventional processes allows a targeted improvement in theirproperties, such as, for example, dimensional stability andtransparency.

The compositions according to the present invention can be prepared onan industrial scale by a simple process, without using microgelscrosslinked by high-energy radiation. The microgels used according tothe present invention permit a less immediate change in modulus betweenthe matrix phase and the dispersed phase, which leads to an improvementin the mechanical properties of the composition.

Also surprisingly, the physical properties, such as, for example,transparency and oil resistance, can be improved when usingthermoplastic elastomers as component (A).

Accordingly, the present invention provides a composition which containsat least one thermoplastic material (A) and at least one microgel (B)based on homopolymers or random copolymers that has not been crosslinkedby high-energy radiation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an image of the composition according to Example 4.

FIG. 2 illustrates an image of the composition according to Example 1.

FIG. 3 illustrates an AFM image of a dynamically vulcanized TPV fromExample 5.

FIG. 4 illustrates hot air storage of the test specimens at differenttemperature.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Microgel or Microgel Phase (B)

The microgel (B) used in the composition according to the presentinvention is a crosslinked microgel based on homopolymers or randomcopolymers. Accordingly, the microgels used according to the presentinvention are crosslinked homopolymers or crosslinked random copolymers.The terms homopolymers and random copolymers are known to the personskilled in the art and are explained, for example, in Vollmert, PolymerChemistry, Springer 1973.

The crosslinked microgel (B) used in the composition according to thepresent invention is a microgel that has not been crosslinked byhigh-energy radiation. High-energy radiation here preferably meanselectromagnetic radiation having a wavelength of less than 0.1 μm.

The use of microgels completely homogeneously crosslinked by high-energyradiation is disadvantageous because it is virtually impossible toimplement on an industrial scale and causes problems associated withworking safety. Furthermore, in compositions prepared using microgelscompletely homogeneously crosslinked by high-energy radiation, tearingeffects between the matrix and the dispersed phase occur on suddenstress, with the result that the mechanical properties, the swellingbehavior and the stress corrosion cracking, etc. are impaired.

The primary particles of the microgel (B) present in the compositionaccording to the present invention preferably exhibit approximatelyspherical geometry. According to DIN 53206:1992-08, primary particlesare the microgel particles dispersed in the coherent phase which can beindividually recognized by means of suitable physical processes(electron microscope) (see e.g. Römpp Lexikon, Lacke und Druckfarben,Georg Thieme Verlag, 1998). An “approximately spherical” geometry meansthat the dispersed primary particles of the microgels recognizably formsubstantially a circular surface when a thin section is viewed using anelectron microscope (see e.g. FIG. 1). As a result, the compositionsaccording to the present invention differ substantially from thedispersed phases produced by the in situ processes, which are generallylarger and have an irregular shape (see e.g. FIG. 3). The substantiallyuniform spherical shape, resulting from the separate preparation processfor the microgels, of the microgel particles dispersed according to theinvention is retained substantially unchanged on dispersion in thethermoplastic material On the basis of this criterion, it is easilypossible to distinguish between the microgel-containing compositionsaccording to the invention and conventionally produced TPEs. Inconventionally produced TPEs, the dispersed phase does not have uniformmorphology, and for that reason individual primary particles cannot belocated therein.

In the compositions according to the present invention there may beused, for example, all known TPEs, especially TPE-Us or TPE-As, as thecontinuous phase. By incorporating the microgels (B) into the knownTPEs, preferably TPE-Us or TPE-As, the dimensional stability under heatof the TPEs, preferably TPE-Us or TPE-As, can surprisingly be improved.The transparency of the microgel-containing compositions according tothe invention based on TPE-U or TPE-A is also improved. The known TPE-Usare not transparent, while the microgel-containing compositionsaccording to the present invention based on TPE-U are transparent. Byincorporating the microgels into TPE-As, it is surprisingly possible togreatly improve their oil resistance, for example, in addition to theiroptical properties, such as transparency.

In the primary particles of the microgel (B) present in the compositionaccording to the present invention, the variation in the diameters of anindividual primary particle, defined as[(d1−d2)/d1]×100,wherein d1 and d2 are any two diameters of any desired section of theprimary particle and d1>d2, is preferably less than 250%, morepreferably less than 200%, most preferably less than 100%.

Preferably at least 80%, more preferably at least 90%, yet morepreferably at least 95%, of the primary particles of the microgelexhibit a variation in the diameters, defined as[(d1−d2)/d1]×100,wherein d1 and d2 are any two diameters of any desired section of theprimary particle and d1>d2, of less than 250%, preferably less than200%, more preferably less than 100%.

The above-mentioned variation in the diameters of the individualparticles is determined by the following process. A TEM image of a thinsection of the composition according to the present invention is firstprepared as described in the Examples. An image is then recorded bytransmission electron microscopy at a magnification of, for example,from 10,000 times to 85,000 times. In an area of 833.7×828.8 nm, thelargest and smallest diameters d1 and d2 are determined on 10 microgelprimary particles. If the variation is less than 250%, more preferablyless than 200%, yet more preferably less than 100%, in all 10 microgelprimary particles, then the microgel primary particles exhibit theabove-defined feature of variation.

If the concentration of the microgels in the composition is so high thatpronounced overlapping of the visible microgel primary particles occurs,the evaluatability can be improved by previously diluting the measuringsample in a suitable manner.

In the composition according to the present invention, the primaryparticles of the microgel (B) preferably have an average particlediameter of from 5 to 500 nm, more preferably from 20 to 400 nm, mostpreferably from 50 to 300 nm (diameter data according to DIN 53206).

Because the morphology of the microgels remains substantially unchangedduring incorporation into the thermoplastic material (A), the averageparticle diameter of the dispersed primary particles correspondssubstantially to the average particle diameter of the microgel used.

In the composition according to the present invention, the microgels (B)that are used advantageously contain at least about 70 wt. %, morepreferably at least about 80 wt. %, most preferably at least about 90wt. %, portions that are insoluble in toluene at 23° C. (gel content).The portion that is insoluble in toluene is determined in toluene at 23°C. For this purpose, 250 mg of the microgel are swelled in 25 ml oftoluene at 23° C. for 24 hours, with shaking. After centrifugation at20,000 rpm, the insoluble portion is separated off and dried. The gelcontent is obtained from the difference between the weighed portion andthe dried residue and is given in percent.

In the composition according to the present invention, the microgels (B)that are used advantageously exhibit a swelling index in toluene at 23°C. of less than about 80, more preferably of less than 60, yet morepreferably of less than 40. For example, the swelling indices of themicrogels (Qi) can preferably be between 1-15 and 1-10. The swellingindex is calculated from the weight of the solvent-containing microgelswelled in toluene at 23° C. for 24 hours (after centrifugation at20,000 rpm) and the weight of the dry microgel:Qi=wet weight of the microgel/dry weight of the microgel.

In order to determine the swelling index, 250 mg of the microgel areallowed to swell in 25 ml of toluene for 24 hours, with shaking. The gelis removed by centrifugation and weighed and then dried at 70° C. untila constant weight is reached and then weighed again.

In the composition according to the present invention, the microgels (B)that are used preferably have glass transition temperatures Tg of from−100° C. to +50° C., more preferably from −80° C. to +20° C.

In the composition according to the present invention, the microgels (B)that are used advantageously have a breadth of glass transition ofgreater than 5° C., preferably greater than 10° C., more preferablygreater than 20° C. Microgels that have such a breadth of glasstransition are generally not completely homogeneously crosslinked—incontrast to completely homogeneously radiation-crosslinked microgels.This has the result that the change in modulus from the matrix phase tothe dispersed phase does not lead to tearing effects between the matrixand the dispersed phase, with the result that the mechanical properties,the swelling behavior and the stress corrosion cracking, etc. areadvantageously affected.

The glass transition temperature (Tg) and the breadth of the glasstransition (ΔTg) of the microgels are determined by differentialscanning calorimetry (DSC). For determining Tg and ΔTg, twocooling/heating cycles are carried out. Tg and ΔTg are determined in thesecond heating cycle. For the determinations, 10 to 12 mg of the chosenmicrogel are placed in a DSC sample container (standard aluminum ladle)from Perkin-Elmer. The first DSC cycle is carried out by first coolingthe sample to −100° C. with liquid nitrogen and then heating it to +150°C. at a rate of 20 K/min. The second DSC cycle is begun by immediatelycooling the sample as soon as a sample temperature of +150° C. has beenreached. Cooling is carried out at a rate of about 320 K/min. In thesecond heating cycle, the sample is again heated to +150° C., as in thefirst cycle. The rate of heating in the second cycle is again 20 K/min.Tg and ΔTg are determined graphically on the DSC curve of the secondheating operation. To that end, three straight lines are plotted on theDSC curve. The first straight line is plotted on the part of the DSCcurve below Tg, the second straight line is plotted on the branch of thecurve passing through Tg with the point of inflection, and the thirdstraight line is plotted on the branch of the DSC curve above Tg. Threestraight lines with two points of intersection are thus obtained. Thetwo points of intersection are each characterized by a characteristictemperature. The glass transition temperature Tg is obtained as the meanof these two temperatures, and the breadth of the glass transition ΔTgis obtained from the difference between the two temperatures.

The microgels (B) based on homopolymers or random copolymers present inthe composition according to the present invention, which microgels havenot been crosslinked by high-energy radiation, can be prepared in amanner known per se (see, for example, EP-A-405 216, EP-A-854171, DE-A4220563, GB-PS 1078400, DE 197 01 489.5, DE 197 01 488.7, DE 198 34804.5, DE 198 34 803.7, DE 198 34 802.9, DE 199 29 347.3, DE 199 39865.8, DE 199 42 620.1, DE 199 42 614.7, DE 100 21 070.8, DE 100 38488.9, DE 100 39 749.2, DE 100 52 287.4, DE 100 56 311.2 and DE 100 61174.5). In patent (applications) EP-A 405 216, DE-A 4220563 and in GB-PS1078400, the use of CR, BR and NBR microgels in mixtures withdouble-bond-containing rubbers is claimed. DE 197 01 489.5 describes theuse of subsequently modified microgels in mixtures withdouble-bond-containing rubbers such as NR, SBR and BR. Microgels areunderstood as being rubber particles which are obtained especially bycrosslinking the following rubbers:

-   BR: polybutadiene-   ABR: butadiene/acrylic acid C1-4 alkyl ester copolymers-   IR: polyisoprene-   SBR: random styrene-butadiene copolymerization products having    styrene contents of from 1 to 60 wt. %, preferably from 5 to 50 wt.    %-   X-SBR: carboxylated styrene-butadiene copolymerization products-   FKM: fluorine rubber-   ACM: acrylate rubber-   NBR: polybutadiene-acrylonitrile copolymerization products having    acrylonitrile contents of from 5 to 60 wt. %, preferably from 10 to    50 wt. %-   X-NBR: carboxylated nitrile rubbers-   CR: polychloroprene-   IIR: isobutylene/isoprene copolymerization products having isoprene    contents of from 0.5 to 10 wt. %-   BIIR: brominated isobutylene/isoprene copolymerization products    having bromine contents of from 0.1 to 10 wt. %-   CIIR: chlorinated isobutylene/isoprene copolymerization products    having chlorine contents of from 0.1 to 10 wt. %-   HNBR: partially and completely hydrogenated nitrile rubbers-   EPDM: ethylene-propylene-diene copolymerization products-   EAM: ethylene/acrylate copolymers-   EVM: ethylene/vinyl acetate copolymers-   CO and-   ECO: epichlorohydrin rubbers-   Q: silicone rubbers-   AU: polyester urethane polymerization products-   EU: polyether urethane polymerization products-   ENR: epoxidized natural rubber or mixtures thereof.

The preparation of the uncrosslinked microgel starting products isadvantageously carried out by the following methods:

-   1. emulsion polymerization-   2. naturally occurring latices, such as, for example, natural rubber    latex, can additionally be used.

The microgels (B) used in the composition according to the presentinvention are preferably those which are obtainable by emulsionpolymerization and crosslinking.

The following free-radically polymerizable monomers, for example, areused in the preparation of the microgels used according to the inventionby emulsion polymerization: butadiene, styrene, acrylonitrile, isoprene,esters of acrylic and methacrylic acid, tetrafluoroethylene, vinylidenefluoride, hexafluoropropene, 2-chlorobutadiene, 2,3-dichlorobutadiene,and also double-bond-containing carboxylic acids, such as, for example,acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc.,double-bond-containing hydroxy compounds, such as, for example,hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxybutylmethacrylate, amine-functionalized (meth)acrylates, acrolein,N-vinyl-2-pyrrolidone, N-allyl-urea and N-allyl-thiourea, secondaryamino(meth)acrylic acid esters, such as 2-tert.-butylaminoethylmethacrylate and 2-tert.-butylaminoethylmethacrylamide, etc.Crosslinking of the rubber gel can be achieved directly during theemulsion polymerization, such as by copolymerization withmultifunctional compounds having crosslinking action, or by subsequentcrosslinking as described herein below. Preferred multifunctionalcomonomers are compounds having at least two, preferably from 2 to 4,copolymerizable C═C double bonds, such as diisopropenylbenzene,divinylbenzene, divinyl ethers, divinylsulfone, diallyl phthalate,triallyl cyanurate, triallyl isocyanurate, 1,2-polybutadiene,N,N′-m-phenylenemaleimide, 2,4-toluylenebis(maleimide) and/or triallyltrimellitate. There come into consideration also the acrylates andmethacrylates of polyhydric, preferably di- to tetra-hydric, C2 to C10alcohols, such as ethylene glycol, 1,2-propanediol, butanediol,hexanediol, polyethylene glycol having from 2 to 20, preferably from 2to 8, oxyethylene units, neopentyl glycol, bisphenol A, glycerol,trimethylolpropane, pentaerythritol, sorbitol, with unsaturatedpolyesters of aliphatic diols and polyols, as well as maleic acid,fumaric acid and/or itaconic acid.

Crosslinking to form rubber microgels during the emulsion polymerizationcan also be effected by continuing the polymerization to highconversions or by the monomer feed process by polymerization with highinternal conversions. Another possibility consists in carrying out theemulsion polymerization in the absence of regulators.

For the crosslinking of the uncrosslinked or weakly crosslinked microgelstarting products following the emulsion polymerization there are bestused latices which are obtained in the emulsion polymerization. Naturalrubber latices can also be crosslinked in this manner.

Suitable chemicals having crosslinking action are, for example, organicperoxides, such as dicumyl peroxide, tert.-butylcumyl peroxide,bis-(tert.-butyl-peroxy-isopropyl)benzene, di-tert.-butyl peroxide,2,5-dimethylhexane 2,5-dihydroperoxide, 2,5-dimethylhexane3,2,5-dihydroperoxide, dibenzoyl peroxide, bis-(2,4-dichlorobenzoyl)peroxide, tert.-butyl perbenzoate, and also organic azo compounds, suchas azo-bis-isobutyronitrile and azo-bis-cyclohexanenitrile, and also di-and poly-mercapto compounds, such as dimercaptoethane,1,6-dimercaptohexane, 1,3,5-trimercaptotriazine and mercapto-tenminatedpolysulfide rubbers, such as mercapto-terminated reaction products ofbis-chloroethylformal with sodium polysulfide.

The optimum temperature for carrying out the post-crosslinking isnaturally dependent on the reactivity of the crosslinker and can becarried out at temperatures from room temperature to about 180° C.,optionally under elevated pressure (see in this connection Houben-Weyl,Methoden der organischen Chemie, 4th Edition, Volume 14/2, page 848).Preferred crosslinkers are peroxides.

The crosslinking of rubbers containing C═C double bonds to formmicrogels can also be carried out in dispersion or emulsion with thesimultaneous partial, or complete, hydrogenation of the C═C double bondby means of hydrazine, as described in U.S. Pat. Nos. 5,302,696 and5,442,009, or optionally other hydrogenating agents, for exampleorganometal hydride complexes.

Enlargement of the particles by agglomeration can optionally be carriedout before, during or after the post-crosslinking.

The preparation process used according to the present invention alwaysyields incompletely homogeneously crosslinked microgels which canexhibit the above-described advantages.

As microgels for the preparation of the composition according to theinvention there may be used both non-modified microgels, which containsubstantially no reactive groups especially at the surface, andmicrogels modified by functional groups, especially microgels modifiedat the surface. The latter can be prepared by chemical reaction of thealready crosslinked microgels with chemicals that are reactive towardsC═C double bonds. These reactive chemicals are especially thosecompounds by means of which polar groups, such as, for example,aldehyde, hydroxyl, carboxyl, nitrile, etc., and also sulfur-containinggroups, such as, for example, mercapto, dithiocarbamate, polysulfide,xanthogenate, thiobenzthiazole and/or dithiophosphoric acid groupsand/or unsaturated dicarboxylic acid groups, can be chemically bonded tothe microgels. The same is also true of N,N′-m-phenylenediamine. Thepurpose of modifying the microgels is to improve the compatibility ofthe microgel with the matrix, in order to achieve a good distributioncapacity during preparation as well as good coupling.

Preferred methods of modification are the grafting of the microgels withfunctional monomers and reaction with low molecular weight agents.

For the grafting of the microgels with functional monomers, there ispreferably used as starting material the aqueous microgel dispersion,which is reacted under the conditions of a free-radical emulsionpolymerization with polar monomers such as acrylic acid, methacrylicacid, itaconic acid, hydroxyethyl (meth)acrylate, hydroxypropyl(meth)acrylate, hydroxybutyl (meth)acrylate, acrylamide, methacrylamide,acrylonitrile, acrolein, N-vinyl-2-pyrrolidone, N-allyl-urea andN-allyl-thiourea, and also secondary amino-(meth)acrylic acid esterssuch as 2-tert.-butylaminoethyl methacrylate and2-tert.-butylaminoethylmethacrylamide. In this manner there are obtainedmicrogels having a core/shell morphology, wherein the shell should behighly compatible with the matrix. It is desirable for the monomer usedin the modification step to be grafted onto the unmodified microgel asquantitatively as possible. The functional monomers are preferablymetered in before crosslinking of the microgels is complete.

Suitable reagents for the surface modification of the microgels with lowmolecular weight agents are especially the following: elemental sulfur,hydrogen sulfide and/or alkylpolymercaptans, such as1,2-dimercaptoethane or 1,6-dimercaptohexane, also dialkyl anddialkylaryl dithiocarbamate, such as the alkali salts of dimethyldithiocarbamate and/or dibenzyl dithiocarbamate, also alkyl and arylxanthogenates, such as potassium ethylxanthogenate and sodiumisopropylxanthogenate, as well as reaction with the alkali or alkalineearth salts of dibutyldithiophosphoric acid and dioctyldithiophosphoricacid as well as dodecyldithiophosphoric acid. The mentioned reactionscan also be carried out in the presence of sulfur, the sulfur beingincorporated with the formation of polysulfide bonds. For the additionof this compound, free-radical initiators such as organic and inorganicperoxides and/or azo initiators can be added.

There comes into consideration also modification ofdouble-bond-containing microgels such as, for example, by ozonolysis aswell as by halogenation with chlorine, bromine and iodine. A furtherreaction of modified microgels, such as, for example, the preparation ofhydroxyl-group-modified microgels from epoxidized microgels, is alsounderstood as being the chemical modification of microgels.

Preferably, the microgels are modified by hydroxyl groups, especiallyalso at the surface thereof. The hydroxyl group content of the microgelsis determined as the hydroxyl number with the dimension mg of KOH/g ofpolymer by reaction with acetic anhydride and titration of the aceticacid liberated thereby with KOH according to DIN 53240. The hydroxylnumber of the microgels is preferably from 0.1 to 100, more preferablyfrom 0.5 to 50, mg of KOH/g of polymer.

The amount of modifying agent used is governed by its effectiveness andthe demands made in each individual case and is in the range from 0.05to 30 wt. %, based on the total amount of rubber microgel used,particular preference being given to from 0.5 to 10 wt. %, based on thetotal amount of rubber gel.

The modification reactions can be carried out at temperatures of from 0to 180° C., preferably from 20 to 95° C., optionally under a pressure offrom 1 to 30 bar. The modifications can be carried out on rubbermicrogels without a solvent or in the form of their dispersion, it beingpossible in the latter case to use inert organic solvents oralternatively water as the reaction medium. The modification ispreferably carried out in an aqueous dispersion of the crosslinkedrubber.

The use of unmodified microgels is especially preferred in the case ofnon-polar thermoplastic materials (A), such as, for example,polypropylene, polyethylene and block copolymers based on styrene,butadiene, isoprene (SBR, SIR) and hydrogenated isoprene-styrene blockcopolymers (SEBS), and conventional TPE-Os and TPE-Vs, etc.

The use of modified microgels is especially preferred in the case ofpolar thermoplastic materials (A), such as, for example, PA, TPE-A, PU,TPE-U, PC, PET, PBT, POM, PMMA, PVC, ABS, PTFE, PVDF, etc.

The mean diameter of the prepared microgels can be adjusted with highaccuracy, for example, to 0.1 micrometer (100 nm)±0.01 micrometer (10nm), so that, for example, a particle size distribution is achieved inwhich at least 75% of all the microgel particles are from 0.095micrometer to 0.105 micrometer in size. Other mean diameters of themicrogels, especially in the range from 5 to 500 nm, can be producedwith the same accuracy (at least 75 wt. % of all the particles arelocated around the maximum of the integrated particle size distributioncurve (determined by light scattering) in a range of ±10% above andbelow the maximum) and used. As a result, the morphology of themicrogels dispersed in the composition according to the presentinvention can be adjusted virtually “point accurately” and hence theproperties of the composition according to the present invention and ofthe plastics, for example, produced there from can be adjusted.

Adjustment of the morphology of the dispersed phase of the TPEs producedaccording to the prior art by in situ reactive processing or dynamicvulcanization is not possible with such precision.

The microgels so prepared can be worked up, for example, byconcentration by evaporation, coagulation, by co-coagulation with afurther latex polymer, by freeze coagulation (see U.S. Pat. No.2,187,146) or by spray-drying. In the case of working up byspray-drying, commercially available flow auxiliaries, such as, forexample, CaCO₃ or silica, can also be added.

Thermoplastic Materials (A)

The thermoplastic materials (A) used in the composition according to theinvention preferably have a Vicat softening temperature of at least 50°C., more preferably of at least 80° C., yet more preferably of at least100° C.

The Vicat softening temperature is determined according to DIN EN ISO306:1996.

In the composition according to the invention, the thermoplasticmaterial (A) is advantageously chosen from thermolastic polymers (A1)and thermoplastic elastomers (A2).

If thermoplastic polymers (A1) are used as starting material for thecomposition according to the invention, then compositions havingthermoplastic elastomer properties are first formed by the incorporationof the microgels used according to the present invention.

If, on the other hand, thermoplastic elastomers (A2) are used asstarting material for the composition according to the presentinvention, then thermoplastic elastomer properties are retained, and theproperties of the thermoplastic elastomers (A2) can be modified in atargeted manner, as shown herein below, by the addition of the microgels(B) of suitable composition and suitable morphology.

Accordingly, the properties of the known TPEs, such as TPE-U and TPE-A,such as especially the dimensional stability under heat and thetransparency of the TPE-Us or the oil resistance of the TPE-As, can beimproved by the incorporation of the microgels (B).

In the composition according to the present invention, the difference inglass transition temperature between the thermoplastic material (A) andthe microgel (B) is advantageously from 0 to 250° C.

In the composition according to the invention, the weight ratiothermoplastic material (A)/microgel (B) is from 1:99 to 99:1, preferablyfrom 10:90 to 90:10, more preferably from 20:80 to 80:20.

If thermoplastic polymers (A1) are used as the thermoplastic materials(A), the weight ratio (A1)/(B) is preferably from 95:5 to 30:70.

If thermoplastic elastomers (A2) are used as the thermoplastic materials(A), then the weight ratio (A2)/(B) is preferably from 98:2 to 20:80,more preferably from 95:5 to 20:80.

Thermoplastic Polymers (A1)

The thermoplastic polymers (A1) which can be used in the compositionaccording to the present invention include, for example, standardthermoplastics, so-called techno-thermoplastics and so-calledhigh-performance thermoplastics (see H. G. Elias Makromoleküle Volume 2,5th Edition, Huthig & Wepf Verlag, 1992, page 443 ff).

The thermoplastic polymers (A1) which can be used in the compositionaccording to the present invention include, for example, non-polarthermoplastic materials, such as, for example, polypropylene,polyethylene, such as HDPE, LDPE, LLDPE, polystyrene, etc., and polarthermoplastic materials, such as PU, PC, EVM, PVA, PVAC,polyvinylbutyral, PET, PBT, POM, PMMA, PVC, ABS, AES, SAN, PTFE, CTFE,PVF, PVDF, polyimide, PA, such as especially PA-6 (nylon), morepreferably PA4, PA-66 (Perlon), PA-69, PA-610, PA-11, PA-12, PA 612,PA-MXD6, etc.

Preferred thermoplastic polymers (A1) include: PP, PE, PS, PU, PC, SAN,PVC and PA.

Thermoplastic Elastomers (A2)

The thermoplastic elastomers (A2) which can be used in the compositionaccording to the present invention include, for example, theabove-mentioned thermoplastic elastomers known from the prior art, suchas the block copolymers, such as styrene block copolymers (TPE-S: SBS,SIS, as well as hydrogenated isoprene-styrene block copolymers (SEBS),thermoplastic polyamides (TPE-A), thermoplastic copolyesters (TPE-E),thermoplastic polyurethanes (TPE-U), the mentioned blends ofthermoplastics and elastomers, such as thermoplastic polyolefins (TPE-O)and thermoplastic vulcanization products (TPE-V), NR/PP blends(thermoplastic natural rubber), NBR/PP blends, IIR (XIIR)/PP blends,EVA/PVDC blends, NBR/PVC blends, etc. Reference may also be made to thedescription of the above-mentioned TPEs from the prior art.

Examples of block polymers which can preferably be used according to theinvention as the thermoplastic elastomer (A2) include the following:

Styrene Block Copolymers (TPE-S)

The three-block structure of two thermoplastic polystyrene end blocksand an elastomeric middle block characterizes this group. Thepolystyrene hard segments form domains, that is to say small volumeelements having uniform characteristics, which act technically asspatial, physical crosslinking sites for the flexible soft segments.According to the nature of the middle block, a distinction is madebetween the following styrene block copolymers: butadiene (SBS),isoprene (SIS) and ethylene/butylene (SEBS) types. Branched types ofblock copolymer can be produced by linking via polyfunctional centers.

Polyether-polyamide Block Copolymers (TPE-A)

The block copolymers based on polyether (ester)-polyamide are formed byinsertion of flexible polyether (ester) groups into polyamide moleculechains. The polyether (ester) blocks form the soft and elastic segments,while the hard polyamide blocks assume the function of the thermoplastichard phase. The hard segments acquire their high strength as a result ofa high density of aromatic groups and/or amide groups, which areresponsible for the physical crosslinking of the two phases by hydrogenbridge formation.

Thermoplastic Copolyesters, Polyether Esters (TPE-E)

Thermoplastic copolyesters are composed of alternate hard polyestersegments and soft polyether components. The polyester blocks, formedfrom diols (e.g. 1,4-butanediol) and dicarboxylic acids (e.g.terephthalic acid), are esterifies in a condensation reaction bylong-chain polyethers carrying hydroxyl terminal groups. Very differenthard regions can be established according to the length of the hard andsoft segments.

Thermoplastic Polyurethanes (TPE-U)

The block copolymers of polyurethane are synthesized by polyaddition ofdiols and diisocyanates. The soft segments formed in the reactionbetween diisocyanate and a polyol act as elastic components undermechanical stress. The hard segments (urethane groups) serving ascrosslinking sites are obtained by reaction of the diisocyanate with alow molecular weiaht diol for chain extension. As in the TPE-S types thefinely divided hard segments form domains which effectquasi-crosslinking via hydrogen bridges or generally via order states inwhich two or more domains enter into relationship with one another.Crystallization of the hard segments may occur thereby. A distinction ismade between polyester, polyether and chemically combinedpolyester/polyether types according to the diol used as startingmonomer.

Regarding the second group of thermoplastic TPEs (A2), the elastomeralloys, reference may be made to the comments given above in connectionwith the prior art. Elastomer alloys which can be used according to theinvention include, for example, the following:

EPDM/PP Blends

EPDM terpolymers are generally used for the rubber phase, polypropyleneis mostly used as the polyolefin. The soft phase can be eitheruncrosslinked (TPE-0) or crosslinked (TPE-V). Where the PP component isdominant, the thermoplastic constitutes the continuous phase. If theelastomer content is very high, the structure can also be reversed, sothat EPDM blends of high PP content result. This class of elastomeralloys therefore covers a wide range of hardnesses. All representativesare distinguished by high resistance to UV radiation and ozone as wellas to many organic and inorganic media. On the other hand, resistance toaliphatic and aromatic solvents is poor to moderate.

NR/PP Blends (Thermoplastic Natural Rubber)

In a similar manner to EPDM, NR can also be compounded with PP and alsowith PP/PE mixtures to form a thermoplastically processable naturalrubber (TPNR). The dynamic crosslinking of NR generally takes place inthe presence of peroxides above 170° C. In comparison with conventionalNR vulcanization products, TPNR blends have markedly higher resistanceto weathering and ozone.

NBR/PP blends

In these polymer blends, pre-crosslinked or partially crosslinkedacrylonitrile-butadiene rubber (NBR) is dispersed as the elastomericphase in the PP hard phase. Characteristic features of these blends arehigh resistance to fuels, oils, acids and alkalis as well as to ozoneand the effects of weathering.

IIR (XIIR)/PP Blends

Butyl or halobutyl rubbers constitute the elastomeric phase constituentsin this class. On the basis of a diene rubber of non-polar nature(comparable NR/IR), the excellent permeation properties of butyl rubbertowards many gases are used for the property profile of the TPE blendsobtainable in a blend with PP.

EVA/PVDC Blends

These are based on a blend of ethylene-vinyl acetate rubber (EVA) andpolyvinylidene chloride (PVDC) as the thermoplastic phase. The propertyprofile in the middle hardness range of from 60 to 80 ShA is marked bygood oil resistance and outstanding resistance to weathering.

NBR/PVC Blends

These polymer blends, produced predominantly for improving theproperties of plasticized PVC, are mixtures of acrylonitrile-butadienerubber (NBR) and polyvinyl chloride (PVC). In particular where betteroil or grease resistance is required, the plasticized PVC grades havinghigh plasticizer contents are no longer usable (plasticizer extraction).In these NBR/PVC blends, NBR acts as a polymeric, non-extractableplasticizer and can be mixed with PVC in virtually any proportion.

Preferred thermoplastic elastomers (A2) include: TPE-U, TPE-A and TPE-V.

Preferred compositions according to the present invention contain thefollowing combinations of components (A) and (B): Thermoplastic material(A) Microgel (B) based on TPE-U SBR (OH-modified), peroxidicallycrosslinked PP SBR (OH-modified), EGDMA- crosslinked PP SBR(unmodified), DVB-crosslinked TPE-A SBR (OH-modified), EGDMA-crosslinked PP NBR, peroxidically crosslinked PA NBR, peroxidicallycrosslinked

The compositions according to the present invention generally behavelike thermoplastic elastomers, that is to say they combine theadvantages of thermoplastic processability with the properties of theelastomers, as described in the introduction in connection with the TPEsfrom the prior art.

The compositions according to the present invention can additionallycomprise at least one conventional plastics additive, such as inorganicand/or organic fillers, plasticizers, inorganic and/or organic pigments,flameproofing agents, agents against pests, such as, for example,termites, agents against marten bite, etc., and other conventionalplastics additives. These can be present in the compositions accordingto the invention in an amount of up to about 40 wt. %, preferably up toabout 20 wt. %, based on the total amount of composition.

The compositions according to the present invention are obtainable bymixing at least one thermoplastic material (A) and at least onecrosslinked microgel (B) that has not been crosslinked using high-energyradiation.

The present invention relates also to the use of crosslinked microgels(B) that have not been crosslinked using high-energy radiation, inthermoplastic materials (A). With regard to the preferred variants ofcomponents (A) and (B), reference may be made to the commentshereinbefore.

The present invention also relates also to a process for the preparationof the compositions according to the invention by mixing at least onethermoplastic material (A) and at least one microgel (B). Thepreparation of the compositions according to the invention is generallycarried out in such a manner that the microgel (B) is preparedseparately before being mixed with the thermoplastic material (A).

The compositions according to the present invention containing(optionally) modified microgel (B) and the thermoplastic material (A)can be prepared by various methods: on the one hand, it is of coursepossible to mix the individual components. Apparatuses suitabletherefore are, for example, mills, multi-roll mills, dissolvers,internal mixers or mixing extruders.

Suitable as mixing apparatuses are also the mixing apparatuses knownfrom rubber and plastics technology (Saechtling Kunststoff Taschenbuch,24th Edition, p. 61 and p. 148 ff; DIN 24450; Mixing of plastics andrubber products, VDI-Kunststofftechnik, p. 241 ff), such as, forexample, co-kneaders, single-screw extruders (with special mixingelements), twin-screw extruders, cascade extruders, degassing extruders,multi-screw extruders, pin extruders, screw kneaders and planetaryextruders, as well as multi-shaft reactors. Preference is given to theuse of twin-screw extruders rotating in the same direction, withdegassing (planetary extruders with degassing).

The further mixing of the compositions according to the presentinvention containing (optionally) modified microgel (B) and thethermoplastic materials (A) with additional fillers and optionallyconventional auxiliary substances, as mentioned above, can be carriedout in conventional mixing apparatuses, such as mills, internal mixers,multi-roll mills, dissolvers or mixing extruders. Preferred mixingtemperatures are from room temperature (23° C.) to 280° C., preferablyapproximately from 60° C. to 200° C.

The present invention relates also to the use of the compositionsaccording to the present invention in the production ofthermoplastically processable molded articles, and to the moldedarticles obtainable from the compositions according to the presentinvention. Examples of such molded articles include: plug-typeconnectors, damping elements, especially vibration dampers and shockabsorbers, acoustic insulating elements, profiles, films, especiallyinsulating films, foot mats, clothing, especially insoles for shoes,shoes, especially ski shoes, shoe soles, electronic components, housingsfor electronic components, tools, decorative molded bodies, compositematerials, moldings for motor vehicles, etc.

The molded articles according to the present invention can be producedfrom the compositions according to the invention by conventionalprocessing methods for thermoplastic elastomers, for example by meltextrusion, calendering, IM, CM and RIM.

The present invention is explained further by the following Examples.However, the present invention is not limited to the disclosure of theExamples.

EXAMPLES

1. Preparation of Microgels (B)

Preparation Example 1

(NBR-based Microgel from Peroxidic Crosslinking (OBR 1102 C))

The preparation of the NBR microgel OBR 1102 C was carried out asdescribed in DE 19701487. An NBR latex was used as starting material.The NBR latex had the following features: content of incorporatedacrylonitrile: 43 wt. %, solids concentration: 16 wt. %, pH value: 10.8,diameter of the latex particles (d₂): 140 nm, particle density: 0.9984g/cm³, the gel content of the latex is 2.6 wt. %, the swelling index ofthe gel portion in toluene was 18.5 and the glass transition temperature(Tg) is −15° C.

7 phr of dicumyl peroxide (DCP) was used in the preparation of OBR 1102C.

Characteristic data of the resulting microgel are summarized in Table 1.

Preparation Example 2

(SBR-based Microgel from Peroxidic Crosslinking (OBR 1046 C))

The preparation of the microgel was carried out by crosslinking an SBRlatex containing 40 wt. % of incorporated styrene (Krylene 1721 fromBayer France) in latex form with 1.5 phr of dicumyl peroxide (DCP) andsubsequently grafting with 5 phr of hydroxyethyl methacrylate (HEMA).

The crosslinking of Krylene 1721 with dicumyl peroxide was carried outas described in Examples 1) to 4) of U.S. Pat. No. 6,127,488, 1.5 phr ofdicumyl peroxide being used for the crosslinking. The underlying latexKrylene 1721 has the following features:

-   solids concentration: 21 wt. %; pH value: 10.4; diameter of the    latex-   particles: d10=40 nm; d_(z)=53 nm; d80=62 nm; O_(spec.)=121;    particle-   density: 0.9673 g/cm³, the gel content of the microgel is 3.8 wt. %,    the swelling index of the gel portion is 25.8 and the glass    transition temperature (Tg) is −31.5° C.

After reaction with 1.5 phr of dicumyl peroxide, the product had thefollowing characteristic data:

-   solids concentration: 21 wt. %; pH value: 10.2; diameter of the    latex-   particles: d10=37 nm; d50=53 nm; d80=62 nm; particle density: 0.9958    g/cm³, the gel content of the microgel is 90.5 wt. %; the swelling    index of the gel portion is 5.8 and the glass transition temperature    (Tg) is −6.5° C.

The hydroxyl modification of the 1.5 phr-crosslinked SBR latex wascarried out by grafting with 5 phr of hydroxyethyl methacrylate. Thereaction with HEMA, stabilization and working up of thehydroxyl-modified latex were carried out as described in U.S. Pat. No.6,399,706, Example 2.

The characteristic data of the hydroxyl-modified SBR gel are summarizedin Table 1.

Before the microgel is used in TPU, it is dried to constant weight at100 mbar in a vacuum drying cabinet from Haraeus Instruments, typeVacutherm VT 6130.

Preparation Example 3

(SBR-based Microgel from Direct Polymerization; Crosslinking with DVB(OBR1126E)

The preparation of this microgel was carried out by copolymerization of23% styrene, 76% butadiene and 1% divinylbenzene in emulsion.

Preparation Example 4

Microgel based on hydroxyl-modified BR, prepared by direct emulsionpolymerization using the crosslinking comonomer ethylene glycoldimethacrylate (OBR 1118).

325 g of the Na salt of a long-chain alkylsulfonic acid (330 g ofMersolat K30/95 from Bayer AG) and 235 g of the Na salt ofmethylene-bridged naphthalenesulfonic acid (Baykanol PQ from Bayer AG)were dissolved in 18.71 kg of water and placed in a 40-litre autoclave.The autoclave was evacuated three times and charged with nitrogen. Then9.200 kg of butadiene, 550 g of ethylene glycol dimethacrylate (90%),312 g of hydroxyethyl methacrylate (96%) and 0.75 g of hydroquinonemonomethyl ether are added. The reaction mixture was heated to 30° C.,with stirring. An aqueous solution consisting of 170 g of water, 1.69 gof ethylenediaminetetraacetic acid (Merck-Schuchardt), 1.35 g ofiron(II) sulfate*7H₂O, 3.47 g of Rongalit C (Merck-Schuchradt) and 5.24g of trisodium phosphate*12H₂O is then metered in. The reaction wasstarted by addition of an aqueous solution of 2.8 g of p-menthanehydroperoxide (Trigonox NT 50 from Akzo-Degussa) and 10.53 g of MersolatK 30/95, dissolved in 250 g of water. After a reaction time of 5 hours,activation was carried out using an aqueous solution consisting of 250 gof water in which 10.53 g of Mersolat K30/95 and 2.8 g of p-menthanehydroperoxide (Trigonox NT 50) are dissolved. When a polymerizationconversion of 95-99% is reached, the polymerization was stopped byaddition of an aqueous solution of 25.53 g of diethylhydroxylaminedissolved in 500 g of water. Unconverted monomers were then removed fromthe latex by stripping with steam. The latex was filtered and stabilizerwas added as in Example 2 of U.S. Pat. No. 6,399,706, followed bycoagulation and drying.

The characteristic data of the SBR gel are summarized in Table 1.

Preparation Example 5

(NBR-based Microgel from Peroxidic Crosslinking (OBR 1102 B))

An NBR-based microgel from peroxidic crosslinking was prepared as inPreparation Example 1 using DCP of 5 instead of 1.5 phr. TABLE 1Properties of the microgels (B) Cross- Gel OH Acid Preparation ProductMicrogel linking D_(z) Ospec. Density content Tg ΔTg number numberExample name type [phr] [nm] [m²/g] [g/cm³] [wt. %] Ql [° C.] [° C.] [mgKOH/g pol.] 1 OBR NBR DCP/7 132 462 1.0236 93.7 7.9 −0.5 15.8 16.4 2.31102 C 2 OBR SBR DCP/1.5 51 117 1.0112 96.3 5.9 4.5 33.8 10.3 8.4 1046 C3 OBR SBR — — — — 83.4 14.7 −58.5 10.6 9.5 13.2 1126E 4 OBR BR EGDMA/ 50166 0.9245 99.1 7.7 −79 7.6 21.9 3.4 1118 5% 5 OBR NBR DCP/5 129 4781.0184 94.3 8.8 −1.5 13.2 18 3.1 1102 BThe abbreviations used in the table have the following meanings:

DCP: dicumyl peroxide

EGDMA: ethylene glycol dimethacrylate

phr: parts per 100 rubber

O_(spec.): specific surface area in m²/g

d_(z): The diameter d _(z) was defined according to DIN 53 206 as themedian or central value, above and below which in each case half of allthe particle sizes lie. The particle diameter of the latex particles wasdetermined by means of ultracentrifugation (W. Scholtan, H. Lange,“Bestimmung der TeilchengröBenverteilung von Latices mit derUltrazentrifuge” [Determination of the particle size distribution oflatices by ultracentrifuge], Kolloid-Zeitschrift und Zeitschrift fürPolymere (1972) Volume 250, Issue 8). The diameter data in the latex andfor the primary particles in the compositions according to the presentinvention are almost identical, because the particle size of themicrogel particles remains practically unchanged during the preparationof the composition according to the invention.

QI: swelling index

Tg: glass transition temperature

ΔTg: breadth of the glass transition

For the determination of Tg and ΔTg, a DSC-2 device from Perkin-Elmer isused.

Swelling Index QI

The swelling index QI was determined as follows:

The swelling index was calculated from the weight of thesolvent-containing microgel swelled for 24 hours in toluene at 23° andthe weight of the dry microgel:Qi=wet weight of the microgel/dry weight of the microgel.

In order to determine the swelling index, 250 mg of the microgel areallowed to swell for 24 hours in 25 ml of toluene, with shaking. The(wet) gel swelled with toluene is weighed, after centrifugation at20,000 rpm, and then dried to constant weight at 70° C. and weighedagain.

OH Number (Hydroxyl Number)

The OH number (hydroxyl number) was determined according to DIN 53240and corresponds to the amount of KOH, in mg, that is equivalent to theamount of acetic acid liberated in the acetylation of 1 g of substanceusing acetic anhydride.

Acid Number

The acid number is determined as already mentioned above according toDIN 53402 and corresponds to the amount of KOH, in mg, that was requiredto neutralize 1 g of the polymer.

Gel Content

The gel content corresponds to the portion that was insoluble in tolueneat 23° C. It was determined as described above.

Glass Transition Temperature

The glass transition temperatures were determined as mentioned above.

Breadth of the Glass Transition

The breadth of the glass transition was determined as described above.

2. General Procedure for the Mixing Process in an Internal Mixer:

The preparation of the compositions according to the invention wascarried out by means of a laboratory internal mixer (Rheocord 90,Rheomix 600 E mixing chamber, Haake) with tangent rotors, compressed-aircooling and a chamber volume of 350 cm³. Mixing was carried out at aspeed of 100 rpm, an initial chamber temperature of 160° C. and a degreeof filling of 70%. Mixtures comprising a rubber microgel(B)/thermoplastic material (A) in the indicated ratios of, for example,80/20, 70/30, 60/40, 50/50, 40/60, 30/70, 20/80, 10/90 are prepared. Tothat end, the thermoplastic was first placed in the mixer and melted inthe course of 4 minutes. Then the microgel is metered in, the die wasclosed and mixing was carried out for 8 minutes. A rise in temperatureoccurs thereby. The torque passes through a maximum with a finalplateau. After mixing, visually homogeneous samples are removed, whichexhibit approximately the coloring of the microgel.

3. Determination of Morphology

The morphology was determined by means of transmission electronmicroscope images (TEM) and by means of atomic force microscopy (AFM).

1. TEM:

Sample preparation for transmission electron microscopic investigations

Cryo-ultramicrotomy

Procedure:

Under cryo conditions, thin sections having a section thickness of about70 nm were prepared by means of diamond knives. In order to improve thecontrast, contrasting with OsO₄ can be carried out.

The thin sections were transferred to copper nets, dried and firstassessed over a large area in the TEM. Then, with 80 kV beam potentialat 12,000 times magnification, displayed area=833.7*828.8 nm,characteristic image sections were stored by means of digital imagingsoftware for documentation purposes and evaluated.

2. AFM: Topometrix Model TMX 2010.

For the investigation, glossy sections were prepared and transferred tothe AF microscope. The images were prepared by the layered imagingprocess.

If the microgel was too highly concentrated, i.e. if the primaryparticles overlap, dilution can be carried out beforehand.

Example 1

(PP-based Composition According to the Invention)

The microgel OBR 1118 from Preparation Example 4 was mixed with PPAtofina PPH 3060 (produced by ATOFINA) as indicated below. Thepreparation of the composition was carried out using a laboratoryextruder (ZSK 25, manufacturer: Krupp Wemer u. Pfleiderer, Stuttgart;screw diameter d=25 mm, L/d>38; throughputs: 2.0 to 5.0 kg/h, speeds:100 to 220 rpm) having shafts running in the same direction. Mixing iscarried out at a speed of from 100 to 220 rpm, an intake-zonetemperature of 160° C. and a throughput of 5 kg/h. Mixtures having aMG/PP weight ratio of 5/95%, 10/90%, 15/85%, 20/80%, 25/75%, 30/70%,35/65% are prepared. To that end, the PP and MG are first metered intothe extruder continuously by means of gravimetric metering scales. Inthe extruder, a rise in temperature to 180 to 195° C. takes place. Afterprocessing, visually homogeneous samples are removed, which haveapproximately the coloring of the microgel.

A conventionally prepared TPE-V (Santoprene Rubber 201-87) from AdvancedElastomer Systems (M1) was used as a reference for the microgel-basedTPE-Vs.

The resulting compositions/test specimens exhibited the followingproperties. TABLE 2 Results of the physical testing of the studiedmicrogel/TPE-V mixtures according to the invention (M2 to M7) and of theTPE-V (M1) Material M 1 M 2 M 3 M 4 M 5 M 6 M 7 M 8 Santoprene Rubber201-87 100 0 0 0 0 0 0 0 Atofina PPH 3060 [%] 0 95 90 85 80 75 70 65OBR1118 [%] 0 5 10 15 20 25 30 35 Hardness, tested immediately Shore A87 — — — 96 92 89 86 Tensile strength [MPa] 15.9 34 30.6 27.1 22.7 19.819.2 18.5 Elongation at tear [%] 530 15 30 57 89 133 210 270 Modulus at100% elongation [MPa] 6.9 — — — — 7.4 7.6 7.9

Example 2

(PP-based Composition According to the Invention)

The microgel from Example 2 (OBR 1046 C) was mixed with a PP Atofina PPH3060 (produced by Atofina) as indicated below. The preparation of thecomposition is carried out using a laboratory extruder (ZSK 25,manufacturer: Krupp Wemer u. Pfleiderer, Stuttgart; screw diameter d=25mm, L/d>38; throughputs: 2.0 to 3.5 kg/h, speeds: 100 to 200 rpm) havingshafts running in the same direction. Mixing was carried out at a speedof from 100 to 220 rpm, an intake-zone temperature of 165° C. and athroughput of 5 kg/h. Mixtures having a MG/PP weight ratio of, forexample, 5/95%, 10/90%, 15/85%, 20/80%, 25/75%, 30/70%, 35/65% areprepared. To that end, the PP and MG were first metered into theextruder continuously by means of gravimetric metering scales. In theextruder, a rise in temperature to 190 to 210C. took place. Afterprocessing, visually homogeneous samples were removed, which haveapproximately the coloring of the microgel.

A conventionally prepared TPE-V (Santoprene Rubber 201-87) from AdvancedElastomer Systems (M1) was used as a reference for the microgel-basedTPE-Vs.

The resulting compositions/test specimens exhibited the followingproperties. TABLE 3 Results of the physical testing of the studiedmicrogel/TPE-V mixtures according to the invention (M2 and M3) and ofthe TPE-V (M1) Material M 1 M 2 M 3 Santoprene Rubber 100 0 0 201-87Atofina PPH 3060 [%] 0 70 65 OBR1046C [%] 0 30 35 Hardness, testedimmediately Shore A 87 93 88 Tensile strength [MPa] 15.9 23.2 19.8Elongation at tear [%] 530 168 250 Modulus at 100% elongation [MPa] 6.98.7 8.3

Example 3

(PP-based Composition According to the Invention)

Microgels (OBR 1126 E) from Example 3 were mixed with a PP Moplen Q 30 P(produced by Montel Polyolefins) as indicated below. The preparation ofthe composition was carried out using a laboratory extruder (ZSK 25,manufacturer: Krupp Werner u. Pfleiderer, Stuttgart; screw diameter d=25mm, L/d>38; throughputs: 2.0 kg/h, speeds: 100 to 190 rpm) having shaftsrunning in the same direction. Mixing was carried out at a speed of from100 to 220 rpm, an intake-zone temperature of 165° C. and a throughputof 5 kg/h. Mixtures having a MG/PP weight ratio of, for example, 5/95%,10/90%, 1 5/85%, 20/80%, 25/75%, 30/70%, 35/65% are prepared. To thatend, the PP and MG are first metered into the extruder continuously bymeans of gravimetric metering scales. In the extruder, a rise intemperature to 175 to 190° C. takes place. After processing, visuallyhomogeneous samples were removed, which have approximately the coloringof the microgel.

A conventionally prepared TPE-V (Santoprene Rubber 201-87) from AdvancedElastomer Systems (M1) was used as a reference for the microgel-basedTPE-Vs.

The resulting compositions/test specimens exhibited the followingproperties. TABLE 4 Results of the physical testing of the studiedmicrogel/TPE-V mixtures according to the present invention (M2 and M3)and of the TPE-V (M1) Material M 1 M 2 M 3 Santoprene Rubber 201-87 1000 0 Moplen Q 30 P [%] 0 70 65 OBR 1126 E [%] 0 30 35 Hardness, testedimmediately Shore A 87 88 85 Tensile strength [MPa] 15.9 16.2 17.8Elongation at tear [%] 530 193 327 Modulus at 100% elongation [MPa] 6.99.2 8.9

Example 4

(TPE-U-based Compositions According to the Present Invention)

The microgel from Preparation Example 2 (OBR 1046C) was used as themicrogel. As the TPU added to the microgel there was used Desmopan 385,a TPE-U from Bayer AG.

The preparation of the composition was carried out using a laboratoryextruder (ZSK 25, manufacturer: Krupp Wemer u. Pfleiderer, Stuttgart;screw diameter d=25 mm, L/d>38; throughputs: 2.0 to 5.0 kg/h, speeds:100 to 220 rpm) having shafts running in the same direction. Mixing wascarried out at a speed of from 100 to 220 rpm, an intake-zonetemperature of 160° C. and a throughput of 5 kg/h. Mixtures having aMG/PP weight ratio of 5/95%, 10/90%, 15/85%, 20/80%, 25/75%, 30/70% areprepared. To that end, the PP and MG are first metered into the extrudercontinuously by means of gravimetric metering scales. In the extruder, arise in temperature to 195° C. takes place. After processing, visuallyand physically homogeneous samples were removed, which haveapproximately the coloring of the microgel and were transparent.

A conventionally prepared TPU (Desmopan 385) (M1) was used as areference for the microgel-based TPE-Us.

Injection Molding:

Standard tensile test specimens were injection-molded from the resultinggranules of the MG-based TPE-Us and of the pure Desmopan 385. This wascarried out using an injection-molding machine (type 320S from Arburg)at a machine temperature of 205-215° C., a ram pressure of 10 bar and atool temperature of 60° C. The residence time of the sample in themachine and in the tool was 50 seconds. The shot was 29.5 g.

FIG. 1 shows an electron microscope image of the material obtained inExample 4. The dispersed, approximately spherical microgels are clearlyvisible.

Preparation of the Test Specimens:

50% F3 standard test rods were prepared from all the samples. This wascarried out for all materials by injection-molding of test sheets. Thetest specimens were prepared from the test sheets. All the standard rodshave a width of 14 mm in the head region and a web width of 7 mm. Thethickness of the standard rods was 2 mm.

Physical Testing:

-   1. Tensile Test

The tensile test of the samples was carried out on 50% F3 standard testrods (see above) according to DIN 53455. The testing was carried outusing a universal testing machine (type 1445, Frank) with optical lengthpick-ups. The measuring range of the force pick-up was 0 to 1000 N. Theresults of the measurements were summarized in Table 5. The followingmachine parameters were specified: preliminary force 0.1 N speed topreliminary force 1 mm/min load 1000 N Vtest 400 mm/min

The breaking elongation and stress at break values of the microgel-basedTPE-Us were above the values of the pure constituent TPU phase even athigh loads. The calculated values were summarized in Table 2.

Shore A Hardness:

As a comparison with room temperature, the test specimens wereadditionally stored at +80° C. and at −2° C. in each case for 64 hoursand conditioned for 1 hour at RT before the measurement. Within thescope of measuring accuracy, the samples with microgel exhibit nosignificant changes in Shore A hardness. The calculated values weresummarized in Table 6.

Determination of Color:

The color of the test sheets was determined according to DIN standardsDIN 5033 and DIN 6174 using a Match Rite CFS57 colour-measuring devicefrom X-Rite GmbH. The calculated color values were summarized in Table6. Although the microgel-containing test sheets have an inherent color,they remained transparent even with a content of 30% MG. TABLE 5 Resultsof the physical testing of the studied microgel/TPU mixtures accordingto the present invention (M2 to M7) and of the TPU Desmopan 385 (M1)Material M 1 M 2 M 3 M 4 M 5 M 6 M 7 Desmopan 385 [%] 100 95 90 85 80 7570 OBR 1046 C [%] 0 5 10 15 20 25 30 Hardness, tested immediately ShoreA 87 87 87 87 85 84 84 Hardness, stored for 64 h at +80° C. Shore A 8785 84 84 82 81 81 Hardness, stored for 64 h at −21° C. Shore A 88 89 8888 87 87 87 Tensile strength [N/mm²] 9.6 19.1 17.9 17.4 16.6 15.8 13.2Elongation at tear [%] 160 450 424 385 362 350 310 Colour L 70.26 56.2454.35 53.39 51.56 50.25 49.90 Colour A −0.86 0.83 1.00 1.44 1.74 2.183.13 Colour B 4.80 10.36 10.77 10.81 11.02 11.18 12.56Hot-air Ageing:

Hot-air ageing was carried out at 130° C. and 180° C., in each case forone hour. The test specimens were then evaluated for appearance, shapeand color. Test specimens which had not been stored in hot air wereevaluated at the same time for comparison purposes. The results areshown in FIG. 4. Surprisingly, it is found that the test specimensaccording to the invention are more dimensionally stable with theaddition of the microgel than without, the dimensional stabilityincreasing as the microgel content increases.

Example 5

(TPE-A-based Compositions According to the Present Invention andComparison Compositions)

Preparation Process

The preparation of the TPE-As was carried out by means of a laboratoryinternal mixer (Rheocord 90, Rheomix 600 E mixing chamber, Haake) withtangent rotors, compressed-air cooling and a chamber volume of 350 cm³.Mixing was carried out at a speed of 100 rpm, an initial chambertemperature of 190° C. and a degree of filling of 70%. Mixtures having arubber microgel/thermoplastic ratio of 70/30 were prepared (samples 1and 2). To that end the thermoplastic (Grilamid L 112 G) was firstplaced in the mixer and melted in the course of 4 minutes. Then themicrogel was metered in, the die was closed and mixing was carried outfor 8 minutes. A rise in temperature occurred thereby (samples 1 and 2:T_(max)=251° C.). The torque passed through a maximum. After mixing,visually and physically homogeneous samples were removed, whichexhibited approximately the coloring of the microgel. This material wasthen granulated.

A conventional TPE-A (sample 5) having the same rubber/thermoplasticratio was prepared as a reference for the microgel-based TPE-Asaccording to the present invention. The PA used had the name (Grilamid L1120 G) from EMS-GRIVORY and the nitrile rubber used has the name(Perbunan NT 3465) from BAYER AG. The crosslinker used is a dicumylperoxide. It has the name Poly-Dispersion E(DIC)D-40 from Rhein ChemieCorporation. It is a 40% blend of DCP in an EPM binder. 5 phr of thechemical were metered in. Mixing of these TPE-As was carried out in thesame mixer, but an initial temperature of 180° C., a rotor speed of 75rpm and a total mixing time of 12 minutes were chosen. The Grilamid L1120 G (64.3 g) was first placed in the vessel. After it had melted, theNBR rubber (Perbunan NT 3465 (149 g) and the Poly-Dispersion E(DIC)D-40crosslinker (18.6 g) were metered in succession and the die was closed.After mixing, visually and physically homogeneous samples were removed.This material was then granulated. The resulting morphology is shown inFIG. 3 a). In FIG. 3 b), an additional 5 phr of the phase mediatorTrans-Polyoctenamer (Vestenamer 8012 from Degussa AG) were metered intothe internal mixer after the addition of the NBR rnbber (Perbunan NT3465), before the crosslinker was added.

As a further reference for the microgel-based TPE-As according to thepresent invention, pure PA (Grilamid L 1120 G (sample 3)) and pure NBRvulcanization product (Perbunan NT 3465 crosslinked with 5 phr ofPoly-Dispersion E(DIC)D-40 (sample 4)) were used.

Injection Molding

Rods were injection-molded from the granules of the TPE-As and the purethermoplastics. This was carried out using a laboratoryinjection-molding machine (Injektometer, Göttfert) at a machinetemperature of 230-240° C., a pressure of 10 bar and a tool temperatureof 120° C. The residence time of the sample was about one minute in themachine and in the tool.

Preparation of the Test Specimens

S2 standard rods were prepared from all the samples. This was carriedout by cutting in the case of the pure thermplastic materials (sample3). The standard rods of all the other samples were stamped out. All theprepared standard rods had a width of only 10 mm in the head regionbecause the injection-molded blanks had a diameter of only 10 mm. Thethickness of the standard rods is 4 mm.

Physical Testing

Tensile Test

The tensile test of the samples was carried out on S2 standard rods (seeabove) according to DIN 53504. The testing was carried out using auniversal testing machine (type 1445, Frank) with optical lengthpick-ups. The measuring range of the force pick-up is 0 to 2000 N. Theresults of the measurements are summarized in Table 1.

The breaking elongation and stress at break values of themicrogel/PA-based TPE-As were between the values of the pure constituentelastomer and thermoplastic phase. The level of properties of aconventionally prepared TPE-A having the same polymers (sample 5) can bereached. When the microgel OBR1102C (Preparation Example 1) having thehigh ACN content was used, the stronger TPE-A was achieved.

Swelling

The swelling of the samples was carried out on S2 standard rods (seeabove) according to DIN 53521 at a temperature of 125° C. and for aduration of 4 days in the reference test liquid IRM 903 (IndustryReference Material, highly hydro-treated heavy naphthene distillate).When the contact time has elapsed, the test specimens were tempered bystorage in unused test agent for 30 minutes at 23° C.

The results of the swelling test in oil are summarized in Table 6. Theswelling in oil of the microgel/PA-based TPE-As was very slight. Theswelling resistance of a conventionally prepared TPE-A containing thesame polymers (PA (Grilamid L 1120 G) from EMS-GRIVORY and (Perbunan NT3465) from BAYER AG) (sample 5) was exceeded by far. When the microgelOBR1102C having the high ACN content was used, the lower swelling in oilwas noted. TABLE 6 Test results of the physical testing of the PAsamples ε at Swelling by Swelling by Sample σ_(B) ε_(B) σ_(max) σ_(max)volume weight No. Material Mpa % MPa % vol. % wt. % 1 OBR1102B/PA 17.7136.5 17.7 136.5 2.3 1.9 2 OBR1102C/PA 18.5 110.2 18.5 110.2 1.6 1.3 3PA (Grilamid L 28.4 81.5 43 7.7 0.9 0.5 1120 G) 4 NBR (Perbunan NT 3.8434.7 3.8 434.7 13.7 12.7 3465) 5 NBR/PA (Grilamid L 14.1 149.7 14.1149.7 11 10 1120 G/(Perbunan NT 3465)

As illustrated in the Examples above according to the present invention,the microgel domains, that is to say the domains of the elastomer phase,are smaller and more uniform by orders of magnitude than the elastomerdomains, formed by dynamic vulcanization, of conventional dynamicallyvulcanized TPVs, both with (>5 to 30 μm) and without phase mediator (>10to 35 μm, FIG. 3).

Although the invention has been described in detail in the foregoing forthe purpose of illustration, it is to be understood that such detail issolely for that purpose and that variations can be made therein by thoseskilled in the art without departing from the spirit and scope of theinvention except as it may be limited by the claims.

1. Composition comprising at least one thermoplastic material (A) and atleast one microgel (B) based on homopolymers or random copolymers thathas not been crosslinked by high-energy radiation.
 2. Compositionaccording to claim 1, wherein primary particles of the microgel (B)exhibit approximately spherical geometry.
 3. Composition according toclaim 2, wherein variation in diameters of an individual primaryparticle of the microgel (B), defined as[(d1−d2)/d1]×100, wherein d1 and d2 are any two diameters of any desiredsection of the primary particle and d1>d2, is less than 250%. 4.Composition according to claim 1, wherein primary particles of themicrogel (B) have an average particle size of from 5 to 500 nm. 5.Composition according to claim 1, wherein the microgels (B) comprise atleast about 70 wt. % portions that are insoluble in toluene at 23° C. 6.Composition according to claim 1, wherein the microgels (B) have aswelling index in toluene at 23° C. of less than about
 80. 7.Composition according to claim 1, wherein the microgels (B) have glasstransition temperatures of from −100° C. to +50° C.
 8. Compositionaccording to claim 7, wherein t the microgels (B) have a glasstransition temperature of greater than about 5° C.
 9. Compositionaccording to claim 1, wherein the microgels (B) are prepared by emulsionpolymerization.
 10. Composition according to claim 1, wherein thethermoplastic materials (A) have a Vicat softening temperature of atleast 50° C.
 11. Composition according to claim 1, wherein thethermoplastic material (A) is selected from thermoplastic polymers (A1)and thermoplastic elastomers (A2).
 12. Composition according to claim 1,wherein the thermoplastic material (A) and the microgel (B) have adifference in glass transition temperature is from 0 to 250° C. 13.Composition according to claim 1, wherein thermoplastic material(A)/microgel (B) have a weight ration from 1:99 to 99:1.
 14. Compositionaccording to claim 13, wherein the weight ratio thermoplastic material(A)/microgel (B) is from 10:90 to 90:10.
 15. Composition according toclaim 14, wherein the weight ratio thermoplastic material (A)/microgel(B) is from 20:80 to 80:20.
 16. Composition according to claim 1 furthercomprising at least one conventional plastics additive.
 17. Compositionaccording to claim 1, prepared by mixing at least one thermoplasticmaterial (A) and at least one microgel (B) based on homopolymers orrandom copolymers that has not been crosslinked by high-energyradiation.
 18. Composition according to claim 1, wherein the microgel(B) contains functional groups.
 19. Process for the preparation ofcompositions according to claim 1 comprising mixing at least onethermoplastic material (A) and at least one microgel (B) based onhomopolymers or random copolymers that has not been crosslinked byhigh-energy radiation.
 20. Process for the preparation of compositionsaccording to claim 20, wherein the microgel (B) is prepared before it ismixed with the thermoplastic material (A).
 21. A molded acticlecomprising a composition according to claim 1.